Can't Move Files to Diamond????

[Flibmeister]

This has to be something simple, but it has me flummoxed.....

I've had my Diamond for a little more than a week, installed half a dozen programs from .cab files, all transferred to the Diamond the same way: connect the Diamond to my laptop via USB in disk mode, go into My Computer and open the Diamond, then drag the .cab file from wherever it was stored on the computer to Internal Storage on the Diamond.

Suddenly, I can't do that anymore. When I open the Diamond in My Computer, I can see all the files, but if I try to drag any files to it, I get the circle-with-a-line-through-it indicator as soon as the cursor enters the window for the Diamond.

Suggestions?